Histopathology is the examination of tissues from the body under a microscope to spot the signs and characteristics of disease. Histology is the study of tissues, and pathology is the study of disease. So taken together histopathology literally means the study of tissues as relates to disease. A histopathology report describes the tissue that has been sent for examination and the features of what the cancer looks like under the microscope. A histopathology report is sometimes called a biopsy report or a pathology report.
The specialist doctor who does the examination under the microscope is called a Pathologist. The tissue that is studied comes from a biopsy or surgical procedure whereby a sample of the suspect tissue is selected and sent to the laboratory. It is then processed and cut into very thin layers (called sections), stained and examined under microscopes to characterize the details of the cells in the tissue. For some diseases, the surgeon can get a sample of the tissue interpreted very quickly through the use of frozen sections. Frozen sections or slices are used sparingly in lymphoma, however, due to problems in interpretation and sampling. In lymphomas, lymph nodes are the tissue most commonly examined in histopathology. For many types of blood cancers, a bone marrow biopsy may also be required for a definitive diagnosis.